The hormones, aldosterone and growth hormone, both produce an antinatriuresis. This action is delayed for an hour or so after administration of these hormones, and the delayed onset of action has led to the hypothesis that these hormones act by inducing the synthesis of RNA and subsequently the synthesis of a protein which in turn is responsible for the antinatriuresis. The use of inhibitor agents has supported this concept. In the research proposed here, experiments are designed to test more directly that RNA synthesis and protein synthesis are stimulated by these hormones.